Electrical switches

ABSTRACT

An electrical switch includes a body, a conductive support member carried by the body, a pair of electrically interconnecting conductive leaf springs carried by said support member and extending in opposite directions therefrom and fixed contacts carried by the body and engageable by the leaf spring. An operating member is pivotally mounted on the body and engageable with the leaf spring to move the leaf spring relative to the fixed contacts, and the switch has a first stable position in which a plunger holds one of the leaf springs stressed, a second stable position, reached by moving the operating member in one angular direction, in which the plunger moves out of engagement with the leaf spring so that the leaf spring is unstressed, and a third unstable position reached by moving the operating member in the opposite angular direction in which the leaf spring is again unstressed.

United States Patent Cryer [54] ELECTRICAL SWITCHES [72] Inventor:Edward Cryer, Higham, near Burnley,

England [73] Assignee: Joseph Lucas (Industries) Limited, Birmingham,England 22 Filed: June 10, 1970 21 Appl.No.: 45,001

[30] Foreign Application Priority Data June 17, 1969 Great Britain..30,534/69 [52] U.S. Cl ..200/6 BB, 200/67 G [5 1] Int. Cl. ..HOlh13/28 [58] Field oiSearch ..200/139 A, 688, 6C, 68A

[56] References Cited UNITED STATES PATENTS 3,305,630 2/1967 Duffield etal ..,...200/67 F 3,322,914 SH 967 Puccini ...200/67 F 2,678,416 5/1954Shewmon ..200/6 C [451 June 13, 1972 FOREIGN PATENTS OR APPLICATIONS489,713 6/1954 ltaly ..200/68 Primary Eraminer-Dzivid Smith, Jr.Attorney-Holman & Stern [57] ABSTRACT An electrical switch includes abody, a conductive support member carried by the body, a pair ofelectrically interconnecting conductive leaf springs carried by saidsupport member and extending in opposite directions therefrom and fixedcontacts carried by the body and engageable by the leaf spring. Anoperating member is pivotally mounted on the body and engageable withthe leaf spring to move the leaf spring relative to the fixed contacts,and the switch has a first stable position in which a plunger holds oneof the leaf springs stressed, a second stable position, reached bymoving the operating member in one angular direction, in which theplunger moves out of engagement with the leaf spring so that the leafspring is unstressed, and a third unstable position reached by movingthe operating member in the opposite angular direction in which the leafspring is again unstressed.

1 Claim, 3 Drawing Figures PATENTEnJumlsn 3,670,115

SHEETBUF 2 INVENTOR AfidRNEYs ELECTRICAL SWITCHES This invention relatesto electrical switches.

A switch according to the invention includes a body, a conductivesupport member carried by the body, a pair of electricallyinterconnected conductive leaf springs carried by said support memberand extending in opposite directions therefrom, fixed contacts carriedby the body and engageable by said leaf springs, and an operating memberpivotally mounted on the body and engageable with said leaf springs tomove said leaf springs relative to said fixed contacts.

In another aspect, a switch according to the invention comprises a body,an electrically conductive leaf spring connected to one terminal on thebody and movable from a first position which the leaf spring assumesunder its own resilience to a position in which the leaf spring isstressed, the leaf spring serving in one of its positions to complete acircuit between said one terminal and a further terminal on the body,and an operating member pivotally mounted on porating a plunger which isresiliently urged towards the leaf spring, the switch having a firststable position in which the plunger holds the leaf spring stressed, asecond stable position,

- reached by moving the operating member in one angular direction, inwhich the plunger moves out of engagement with the leaf spring so thatthe leaf spring assumes said first position, the switch having athird,unstable position, reached by moving the operating member in theopposite angular direction from the first stable position, movement ofthe operating member in said opposite angular directioncausing theplunger to move up a ramp surface on the body so that the plunger isdisengaged from the leaf spring, which assumes said first position, theoperating member returning to said first stable position when it isreleased under the action of the resilient means acting on the plunger.

An example of the invention is illustrated in the accompanying drawings,in which:

FIGS. 1 and 2 respectively are diagrammatic sectional plan and sideviews of an electrical switch; and

FIG. 3 is an enlarged view similar to FIG. 1 but with the switch in adifferent position.

Referring to the drawing the switch includes a hollow moulded syntheticresin body having a base 11, side walls and'an end wall 12. Extendingupwardly from the base 11 is a pin 9 serving to support a rotor 8 forangular movement. The rotor 8 has an operating lever 7 secured thereto,and the hollow body is closed by a plate 6 through which the rotorextends. Integrally formed with the rotor 8 is a hollow spigot 13 whichextends towards the wall 12. Slidably mounted in the the body andincorspigot 13 is an insulating plunger 14 which is urged by a spring 5,housed within the spigot 13, towards the wall 12. Mounted on the innersurface of the wall 12 is a U-shaped conductive support member 15 whichis electrically connected to a blade terminal 20 on the exterior of thebody. The free ends of the limbs of the support member 15 are formedwith slots and engaged with the support member 15 is a conductive springstrip 17. The strip 17 is engaged in the slots and the edges of theslots are deformed to grip the strip 17 and so retain it in position.Between the limbs of the member 15 the strip 17 is bent to define aV-shaped portion 18 with its apex adjacent the wall 12, the end portionsof the strip 17 extending from the limbs of the member 15 in oppositedirections to define a pair of conductive leaf springs 19, 21. At itsfree end the leaf spring 19 carries a downwardly directed contact 22,while the free end of the leaf spring 21 carries an upwardly directedcontact 23 and a downwardly presented contact 24. Secured to the bodyimmediately above the free end of the leaf springl9 is a fixed contact25 which is engaged by the contact 22 in the rest position of the leafspring 19. Adjacent the free end of the leaf spring 21, the body carriesa pair of fixed contacts 26, 27 which are spaced apart'in a verticaldirection, the contact 26 being engaged by the contact 23 in the restposition of the leaf spring 21, and the contact 27 being engageable bythe contact 24 upon flexure of the leaf spring 21 towards the wall 12.Moreover, adjacent the strip 26 the body is formed with an inwardlydirected flange 28 which presents a ramp surface 29 to the lunger 14.

e contacts 25, 26, 27 are electrically connected to respective externalterminals of the switch, and the operation of the switch is as follows.In the ofi position shown in FIG. 3, the plunger 14 rests in a stableposition at the bottom of the ramp surface 29, with the contact 24engaging the contact 27 and the contact 22 engaging the contact 25.Clockwise movement from this position moves the operating member to aposition seen in FIG. 1 in which the spigot 13 extends generally atright angles to the wall 12, and the plunger 14 is engaged in theV-shaped portion 18 of the strip 17. In this position the contact 23 isengaged with the contact 26.

- Further movement of the operating member relative to the body in aclockwise direction causes the plunger 14 to ride out of the portion 18of the strip 17 and onto the leaf spring 19, thereby flexing the leafspring 19 towards the base 12 and disengaging the contacts 22 and 25.The contacts 23, 26 remain engaged. These three positions are stable,but by pivoting the operating member in a counter clockwise directionfrom the position shown in FIG. 3, the plunger 14 is caused to engagethe ramp surface 29, and rides up the ramp surface as permitted bycompression of the spring 5, thereby permitting the leaf spring 21 toreturn to its rest position wherein the contact 23 engages the contact26, and the switch is in the same electrical position as in FIG. 2. Whenthe operating member is released while the plunger 14 is engaged withthe ramp surface 29, the various parts return to the position shown inFIG. 3.

In one example of the use of the switch described above the switch isutilized to control the operation of a two speed windscreen wiper motor.In the off position shown in FIG. 3, the motor is short-circuited assoon as the wipers reach their parking position. In the first operativeposition shown in FIG. 2 the motor is operated at its slow speed, and inthe second operative position the motor is operated at its fast speed.One or more wipes of the screen are readily attainable by moving theswitch to its unstable operative position against the action of thespring 5. Where the motor has a parking switch, momentary operation ofthe switch in this way will give a single wipe.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. An electrical switch including a body, a conductive support membercarried by the body, a pair of electrically interconnected conductiveleaf springs carried by said support member and extending in oppositedirections therefrom, fixed contacts carried by the body and engageableby said leaf springs, an operating member pivotally mounted on the bodyand incorporating a spring loaded plunger engageable with said leafsprings to move said leaf springs relative to said fixed contacts, saidleaf springs being integral with one another, and said switchincorporating detent means defining a first switch position in whichsaid plunger engages a V-shaped portion defined by said leaf springs,neither leaf spring being stressed in this first switch position, theoperating member being movable in one angular direction from said firstswitch position to a second stable switch position in which one of theleaf springs is stressed, and said operating member being movable in theopposite angular direction from said first switch position to a thirdswitch position in which said other leaf spring is stressed, said switchincorporating a ramp surface which is engaged by said plunger when saidswitch is moved beyond said third switch position, said ramp surfacemoving said plunger out of engagement with the leaf springs to define afourth unstable switch position.

1. An electrical switch including a body, a conductive support membercarried by the body, a pair of electrically interconnected conductiveleaf springs carried by said support member and extending in oppositedirections therefrom, fixed contacts carried by the body and engageableby said leaf springs, an operating member pivotally mounted on the bodyand incorporating a spring loaded plunger engageable with said leafsprings to move said leaf springs relative to said fixed contacts, saidleaf springs being integral with one another, and said switchincorporating detent means defining a first switch position in whichsaid plunger engages a V-shaped portion defined by said leaf springs,neither leaf spring being stressed in this first switch position, theoperating member being movable in one angular direction from said firstswitch position to a second stable switch position in which one of theleaf springs is stressed, and said operating member being movable in theopposite angular direction from said first switch position to a thirdswitch position in which said other leaf spring is stressed, said switchincorporating a ramp surface which is engaged by said plunger when saidswitch is moved beyond said third switch position, said ramp surfacemoving said plunger out of engagement with the leaf springs to define afourth unstable switch position.